base tests: make sure to fail CI if tests need formatting

Author: matthiaskrgr

ci/base-tests.sh

@@ -50,7 +50,7 @@ done
 # switch back to master
 rustup default master
 
-if [ "${needs_reformatting}" = true ] ; then
+if [ "${needs_reformatting}" == true ] ; then
     echo "Tests need reformatting!"
     exit 2
 fi